The present invention relates to a device for changing over a vehicle provided with wheels to a track vehicle.
Devices or vehicles which can travel on the wheels but be changed over to travel on tracks normally include two chain or caterpillar aggregates connected with the chassis of the vehicle and positioned at two opposite sides thereof. Each aggregate supports at least two wheels which serve for driving and steering the track and over which the track runs, whereby a torque translation device connected to the drive axle of the automotive vehicle for driving the drive wheel corresponds to each chain or aggregate, and brakes, which are actuated separately from the vehicle by the steering control device, are provided for both chain or track aggregates.
A change-over arrangement with track of this type has been disclosed, for example in DE-PS 1,045,250. This conventional device offers the possibility to change over the wheeled vehicle to the track vehicle and vice versa depending on soil conditions. Two chain or track aggregates are formed identically to each other and have the length which exceeds the length of the vehicle whereby the drive wheel of the track in the assembled position is arranged in the tail region of the vehicle which the steering wheel of the track or change projects forwardly beyond the vehicle. The torque translation device includes two wheels connected to each other to be driven by a translation chain. On of these wheels is mounted, after the removal of the respective rear wheel from the drive axle, on this axle, while the other wheel is connected to the chain drive wheel. The chain steering wheel at the front end of the chain aggregate is coaxial with the brake drum which, after the removal of the respective front wheel, is also connected to the front axle stump of the vehicle by the rod or bar so that the steering device of the wheeled vehicle also serves for steering the track vehicle because the steering turning cycle over the connected rod leads to a respective actuation of the drum of the brake and thus to the braking of the track on the one side of the vehicle only which causes, as known, the change of direction or turn. After changing over, the track or chain aggregates, which replaced the wheels removed from the vehicle, are arranged substantially below the vehicle, and project laterally beyond the vehicle with the rear torque translation device and the front brake device.
The disavantages of the known device are the irksome conversion which leads to the placement of the tracks below the vehicle, which makes the jacking up of the vehicle necessary and the vehicle wheels must be removed from the body of the vehicle. A comparatively great weight of the tracks, which is limited by the length of the aggregates and the torque translation device and brake device, presents further difficulties because to bring the chain or track aggregates to their positions before assembling is not simple at all. In addition to securing of the track aggregates or their elongated frames to the vehicle it is necessary to connect the torque translation device to the drive axle and the brake-actuating rods to the front axle stump. These operations can be carried out only in a special service. Therefore often the aforedescribed conversion of the wheeled vehicle to the track vehicle to adapt to changing soil conditions are not realized in practice. Also, storage of heavy track components during the operation of the vehicle on the wheels can present further difficulties. It is particularly impossible in practice or at least very undesirable to carry along two track aggregates, during the travelling on the wheels, as roof poles or hanging loads. Thus, the possibilities of changing over a wheeled vehicle to a track vehicle are limited and the known device has no flexibility for such charging over.
DE-AS 18 07 390 discloses a tractor which includes two chain aggregates positioned laterally of the vehicle, and the wheels remain on the vehicle during the track operations. The drive wheel of the track is connected coaxially to the drive axle. However, the known device can not provide a pure tracks travel and track act as supports for the vehicle running on the wheels. This presents a problem because the track arrangements are stationarily positioned on the vehicle and can be lowered to an operative position from the lifted inoperative position by means of a pressure roller carriage. Thereby the front drive wheel of the track is positioned behind the front wheel which also acts as a steering wheel in the additional track operation. Here short additional tracks can be utilized, and the pure track travel of the vehicle is not possible. The track arrangements should be either removed from the vehicle or always be carried along by the vehicle which leads to a substantial enlargement of the width of the vehicle.